1. Field of the Invention
This invention relates to a bin tunnel for use with a truck box of a truck to load content into the truck box using a bin that is sized to fit into the bin tunnel when the bin tunnel is in an open position, the bin tunnel having collapsible sides, resulting in a small footprint when the bin tunnel is in a closed position.
2. Description of the Prior Art
It is known to have bin tunnels to load the content of a bin into a truck box of a truck. Bin tunnels have a closed position in which an outer wall of the bin tunnel is flush with an outer wall of the truck box. When the truck is being driven, the bin tunnel is in the closed position. When the truck is stopped and it is desired to empty the contents of one or more bins into the truck box, the bin tunnel is pulled outward from the truck box to an open position. The bin tunnel and the bin to be emptied are appropriately sized relative to one another so that the bin will fit into the bin tunnel when the bin tunnel is in the open position. A bin lifting mechanism is mounted on the inner wall of the bin tunnel to lift up the bin and turn it upside down to empty the contents into the truck box. The inner wall of the bin tunnel is a recessed wall built into the truck box. Where the bin contains items to be shredded, the truck box can contain a shredder or the truck can simply be a collection vehicle that delivers the contents to another location to be shredded. A bin tunnel is described in Yamamoto et al U.S. Pat. No. 6,588,691 issued Jul. 8, 2003.
The extendable and retractable portion of existing bin tunnels has the same internal dimensions whether the bin tunnel is in the open position or in the closed position. The truck box must be designed to accommodate the size of the bin tunnel in the closed position and the available space within the bin tunnel for storage of content, whether shredded or unshredded, or other storage is reduced by the depth of the bin tunnel as the extendable and retractable portion of the bin tunnel must fit inside the truck box when the bin tunnel is in a closed position. The inner wall must be recessed by the same distance that the bin tunnel extends beyond the side wall of the truck box. when the bin tunnel is in the open position. Since the usable width of the truck box is reduced by the inner wall, this reduces the size of the payload of the truck and decreases the efficiency of the truck. Also, for mobile document systems where content is collected by a truck for shredding at another location, since the bin tunnel narrows the inner width of the truck box by the same distance that the bin tunnel extends beyond the sidewall of the truck box when the bin tunnel is in the open position, a standard size fork lift will not fit into the truck box for unloading.
With existing bin tunnels, when the bin tunnel is in a closed position, there is still sufficient space within the bin tunnel for a person to access the interior of the truck body through the bin tunnel. This access can be a security problem when the contents of the truck box are not shredded.